1. Barker, W.G.: Introduction to the analysis of the Data Encryption Standard (DES), Aegean Park Press, Laguna Hills, California, 1991
2. Biham, E. and Shamir, A.: Differential Cryptoanalysis of the Data Encryption Standard, 1993, published by Springer New York
3. Cox,I. J., Kilian.J., Leighton,T. and Shamoon.T.: Secure Spread Spectrum Watermarking for Multimedia, Copyright (c) 1995 by NEC Research Institute, Inc, http://www.neci.nj.nec.com/homepages/ingemar/
4. Dittmann,J., Steinmetz,A.: Konzeption für Sicherheitsmechanismen für das Projekt DiVidEd, GMD-Studie, 1997
5. Frauenhofer Institute for Computer Graphics: http://www.igd.fhg.de/www/igda8/projects/tie/tie.htm